Method for manufacturing combined substrate having silicon carbide substrate

Abstract

A connected substrate having a supporting portion and first and second silicon carbide substrates is prepared. The first silicon carbide substrate has a first backside surface connected to the supporting portion, a first front-side surface, and a first side surface connecting the first backside surface and the first front-side surface to each other. The second silicon carbide substrate has a second backside surface connected to the supporting portion, a second front-side surface, and a second side surface connecting the second backside surface and the second front-side surface to each other and forming a gap between the first side surface and the second side surface. A filling portion for filling the gap is formed. Then, the first and second front-side surfaces are polished. Then, the filling portion is removed. Then, a closing portion for closing the gap is formed.

1 . A method for manufacturing a combined substrate, comprising the steps of:
 preparing a connected substrate having a supporting portion and first and second silicon carbide substrates, said first silicon carbide substrate having a first backside surface connected to said supporting portion, a first front-side surface opposite to said first backside surface, and a first side surface connecting said first backside surface and said first front-side surface to each other, said second silicon carbide substrate having a second backside surface connected to said supporting portion, a second front-side surface opposite to said second backside surface, and a second side surface connecting said second backside surface and said second front-side surface to each other and forming a gap between said first side surface and said second side surface;   forming a filling portion for filling said gap;   polishing said first and second front-side surfaces after the step of forming said filling portion;   removing said filling portion after the step of polishing; and   forming a closing portion for closing said gap after the step of removing.   
     
     
         2 . The method for manufacturing the combined substrate according to  claim 1 , wherein the step of forming said closing portion is performed by epitaxially growing said closing portion on said first and second silicon carbide substrates. 
     
     
         3 . The method for manufacturing the combined substrate according to  claim 1 , wherein the step of removing said filling portion is performed by means of a dry process. 
     
     
         4 . The method for manufacturing the combined substrate according to  claim 1 , wherein the step of forming said filling portion is performed using at least one of a metal, a resin, and silicon. 
     
     
         5 . The method for manufacturing the combined substrate according to  claim 1 , wherein the step of removing said filling portion and the step of forming said closing portion are performed in a continuous manner in a chamber.